Processes and devices have been used for image processing in which a nipping mechanism can be applied to an image processing apparatus which is being represented by electro photographic copiers, laser printers or facsimile machines. A nipping mechanism is usually provided in a fixing device disposed downstream from a transfer belt for transporting a sheet having a toner image transferred through a photosensitive drum. A nipping mechanism comprises a fixing roller having a heater embedded therein, and a pressure roller disposed in opposed relation to the fixing roller while allowing the lower portion thereof to be in close contact with the fixing roller.
In such an electrographic apparatus generally a fixing device in a two-roll system composed of a heating roll and a pressure roll, that is being kept in contact with each other, is employed passing through the recording medium over the surface. An unfixed toner image can be formed through the nip zone. A nip zone is formed when the recording medium is in contact with both rolls. Then the toner in the electrographic apparatus is molten by heat and pressure so that the toner image is fixed on the surface of the recording medium as a permanent image. As the case may be in place of the heating roll and pressure roll, the heating member of each has an endless belt shape.
As xerographic imaging systems continue to increase in speed, the need to provide an adequate nip width to a fuser toner and then to a media also increases. Referring to FIG. 1, labeled as prior-art, a graph 100 illustrates traditional roll pairs. The graph shows that traditional roll pairs are limited due to a relationship between roll diameters, elastomer thickness, and the available load. For example, to achieve a 30 ms (milliseconds) dwell time when a 100 ppm (pulse position modulation) rate is required, a nip width of 14.04 mm (millimeters) is required. As speeds increase to 150 ppm, an equivalent nip grows to 21.06 m. At 200 ppm the nip width is 28.08 mm. In the graph the load (pounds) 102 defines the horizontal axis and dwell time (ms) 104 defines the vertical axis. The graph also shows the representations in specific values 106 when plotted.
Hence there is a need to provide an adequate nip width to a fuser toner by using a nipping mechanism. As xerographic imaging systems continue to increase in speed, a nipping mechanism with fusing enhancement that can be used in image processing for providing improved performance is needed. Ideally the sheet nipping mechanism and nipping mechanism for fixing devices can be enhanced by using a method of linear fusing in nipping mechanism.